Establishment of Etv5 gene knockout mice as a recipient model for spermatogonial stem cell transplantation

Xianyu Zhang; Xin Zhao; Guoling Li; Mao Zhang; Pingping Xing; Zicong Li; Bin Chen; Huaqiang Yang; Zhenfang Wu

doi:10.1242/bio.056804

Establishment of Etv5 gene knockout mice as a recipient model for spermatogonial stem cell transplantation

Biol Open. 2021 Jan 6;10(1):bio056804. doi: 10.1242/bio.056804.

Authors

Xianyu Zhang^{1

2}, Xin Zhao², Guoling Li², Mao Zhang², Pingping Xing², Zicong Li², Bin Chen³, Huaqiang Yang⁴, Zhenfang Wu⁴

Affiliations

¹ College of Animal Science and Technology, Hunan Agricultural University, Changsha, Hunan 410128, China.
² National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China.
³ College of Animal Science and Technology, Hunan Agricultural University, Changsha, Hunan 410128, China yangh@scau.edu.cn chenbin7586@126.com wzf@scau.edu.cn.
⁴ National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China yangh@scau.edu.cn chenbin7586@126.com wzf@scau.edu.cn.

Abstract

Spermatogonial stem cell (SSC) transplantation is an alternative reproductive method to achieve conservation and production of elite animals in livestock production. Creating a recipient animal without endogenous germ cells is important for effective SSC transplantation. However, natural mutants with depletion of SSCs are difficult to obtain, and drug ablation of endogenous germ cells is arduous to perform for practical use. In this study, we used mouse models to study the preparation of recipients with congenital germ cell ablation. We knocked out (KO) Ets-variant gene 5 (Etv5) in mice using the CRISPR/Cas9 system. The testicular weight of Etv5^-/- mice was significantly lower than that of wild-type (WT) mice. The germ cell layer of the seminiferous tubules gradually receded with age in Etv5^-/- mice. At 12 weeks of age, the tubules of Etv5^-/- mice lacked almost all spermatogenic cells with a Sertoli cell-only phenotype, and sperm were completely absent in the epididymis. We subsequently transplanted allogeneic SSCs with enhanced green fluorescent protein (EGFP) into 3- (immature) or 7-week-old (mature) Etv5^-/- mice. Partial restoration of germ cell layers in the seminiferous tubules and spermatogenesis was observed in all immature testes but not in mature adult testes at 2 months post-transplantation. The presence of heterologous genes Etv5 and EGFP in recipient testicular tissue and epididymal sperm by PCR indicated that sperm originated from the transplanted donor cells. Our study demonstrates that, although Etv5^-/- mice could accommodate and support foreign germ cell transplantation, this process occurs in a quite low efficiency to support a full spermatogenesis of transplanted SSCs. However, using Etv5^-/- mice as a recipient model for SSC transplantation is feasible, and still needs further investigation to establish an optimized transplantation process.

Keywords: Etv5; Gene knockout; Spermatogenesis; Spermatogonial stem cells; Transplantation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult Germline Stem Cells / cytology*
Adult Germline Stem Cells / metabolism*
Alleles
Animals
CRISPR-Cas Systems
DNA-Binding Proteins / deficiency
DNA-Binding Proteins / genetics*
Gene Editing
Genotype
Mice
Mice, Knockout*
Models, Animal*
Stem Cell Transplantation*
Transcription Factors / deficiency
Transcription Factors / genetics*
Transplantation, Homologous

Substances

DNA-Binding Proteins
Etv5 protein, mouse
Transcription Factors